Even President Biden is getting involved in this Pa. House race. He’s endorsed Heather Boyd.

President Joe Biden made a last-minute endorsement in a Pennsylvania special election that will decide which party controls the state House.

Biden endorsed Heather Boyd, the Democratic candidate in a Delaware County special election. Boyd and Republican candidate Katie Ford are vying to fill the vacancy in the 163rd House District created by the resignation of former State Rep. Mike Zabel, a Democrat who resigned after three public accusations of sexual harassment.

» READ MORE: This Upper Darby race will determine who controls the Pa. House. Here’s what’s at stake.

It’s unusual for a sitting U.S. president to get involved in state House races. But with so much riding on the election in Delaware County, electing Boyd “could not be more important,” Biden first told The Inquirer in a statement.

“With control of the Pennsylvania House of Representatives on the line, this race will determine the future of so many fundamental freedoms that Pennsylvanians hold dear,” Biden said. “That’s why I am incredibly proud to endorse Heather Boyd for Pennsylvania House District 163. Heather is an experienced public servant who will protect a woman’s right to make her own health care decisions, stand up for common sense gun safety laws and expand access to voting rights.”

Biden is the latest and most high-profile politician to endorse Boyd. She’s racked up endorsements from Gov. Josh Shapiro, state House Speaker Joanna McClinton, and her former boss, U.S. Rep. Mary Gay Scanlon (D., Delaware). Shapiro put out a 30-second ad earlier this month asking Upper Darby voters to support Boyd, stressing that control of the House will determine abortion access in the state.

Democrats have gone all in on maintaining the narrow majority they gained in February, spending nearly $1 million on ad buys, mailers, and polling, according to campaign finance filings. Republicans have spent only a fraction of that in the Democratic-leaning district, which has shifted more blue since Zabel flipped the seat in 2018.

Boyd has focused her campaign on maintaining her party’s House majority — and by extension, reproductive rights. She’s focused on preventing a constitutional amendment that would declare abortion is not a constitutional right in Pennsylvania, a change reproductive rights activists say could open the door to a state abortion ban. The Pennsylvania General Assembly approved the measure last year, in the wake of the U.S. Supreme Court’s reversal of Roe v. Wade, when Republicans controlled both the House and Senate. But it must be passed again this year to get before voters. Constitutional amendments cannot be vetoed by a governor.

Ford has emphasized former Rep. Zabel’s misconduct — and Boyd’s knowledge of it — along with her drive to improve her community and the 163rd District, which is made up of Upper Darby and Darby Townships and Collingdale, Clifton Heights, and Aldan Boroughs.

Democrats currently hold a one-seat majority in the state House of Representatives, 101-100. Voters in Montour County and parts of Northumberland County will also vote in a special election Tuesday, where the GOP-majority district is expected to elect the Republican candidate.

Whoever controls the House will set the agenda on state policies for elections, school funding, taxes, abortion access, and more.

Democrats took control just three months ago, after more than 12 years in the minority. Since taking control, House Democrats have boasted the passage of a long-sought antidiscrimination bill for LGBTQ residents and gun reforms in their first days in the majority. But Republicans hold the majority in the Senate, and legislation must pass both houses before it can get Shapiro’s signature and become law.

The Pennsylvania GOP did not respond to a request for comment.